[RELEASE NOTES + DOCS] CLI tunnel feature should use all tunnel servers

[jackkleeman]

Currently the CLI tunnel is a bit of a special case. It talks to only a single tunnel server eg :19082, which it is assigned randomly after first hitting 19080, and it then asks users to register a tunnel url that has a particular port, like tunnel://foo:9082 which means their restate env will hit the same tunnel server. This means that on the infra side, we have to maintain the ability for restate to hit a particular tunnel server using a port and a dns name, and this is potentially cross zone, which is not desirable. Instead, the cli should talk to all the tunnel servers (as discovered from the srv record eg tunnel.us.restate.cloud, and the restate environment should talk to its zone local tunnel servers to try and find a connection. This behaviour matches the standalone tunnel client that people run in their clusters. In the CLI we have a slightly simplified client however, as we do not handle tunnel draining mechanism and we don't handle the srv record changing.

In addition, the tunnel:// urls that map to a single local port are confusing. Instead we move to a generic local proxy approach, where you can register any url, providing --tunnel-name to specify that it should go through the tunnel for your environment. This will unify CLI + standalone tunnels, so that users don't have to build the tunnel url themselves.

eg:

restate cloud env tunnel --tunnel-name foo
restate dp register --tunnel-name foo http://localhost:9080
# you can even proxy to external urls
restate dp register --tunnel-name foo https://my-worker.workers.dev

Summary of changes:

• We have to generate tunnel names client side, as we need to reach out to all tunnel servers simultaneously so it is tricky to let the server generate it
• Resolve srv and connect to all tunnel servers
• Generic forward proxy based on incoming url, matching standalone tunnel client
• Change register command to accept normal urls + --tunnel-name
• Get proxy base url at registration time from describe environment response, not local config so that we have more flexibility eg for byoc clusters

[jackkleeman]

this has been copied over verbatim from the standalone tunnel client

[jackkleeman]

this proxy logic is very similar to what we use in the standalone tunnel client

[github-actions]

Test Results

 5 files   -   2   5 suites   - 2   1m 18s ⏱️ - 1m 18s
34 tests  -  13  34 ✅  -  13  0 💤 ±0  0 ❌ ±0 
52 runs   - 148  52 ✅  - 148  0 💤 ±0  0 ❌ ±0 

Results for commit c693d98. ± Comparison against base commit 3369991.

This pull request removes 47 and adds 34 tests. Note that renamed tests count towards both.

dev.restate.sdktesting.tests.CallOrdering ‑ ordering(boolean[], Client)[1]
dev.restate.sdktesting.tests.CallOrdering ‑ ordering(boolean[], Client)[2]
dev.restate.sdktesting.tests.CallOrdering ‑ ordering(boolean[], Client)[3]
dev.restate.sdktesting.tests.Cancellation ‑ cancelFromAdminAPI(BlockingOperation, Client, URI)[1]
dev.restate.sdktesting.tests.Cancellation ‑ cancelFromAdminAPI(BlockingOperation, Client, URI)[2]
dev.restate.sdktesting.tests.Cancellation ‑ cancelFromAdminAPI(BlockingOperation, Client, URI)[3]
dev.restate.sdktesting.tests.Cancellation ‑ cancelFromContext(BlockingOperation, Client)[1]
dev.restate.sdktesting.tests.Cancellation ‑ cancelFromContext(BlockingOperation, Client)[2]
dev.restate.sdktesting.tests.Cancellation ‑ cancelFromContext(BlockingOperation, Client)[3]
dev.restate.sdktesting.tests.Combinators ‑ awakeableOrTimeoutUsingAwakeableTimeoutCommand(Client)
…

dev.restate.sdktesting.tests.AwakeableIngressEndpointTest ‑ completeWithFailure(Client)
dev.restate.sdktesting.tests.AwakeableIngressEndpointTest ‑ completeWithSuccess(Client)
dev.restate.sdktesting.tests.BackwardCompatibilityTest$NewVersion ‑ completeAwakeable(Client)
dev.restate.sdktesting.tests.BackwardCompatibilityTest$NewVersion ‑ completeRetryableOperation(Client)
dev.restate.sdktesting.tests.BackwardCompatibilityTest$NewVersion ‑ proxyCallShouldBeDone(Client)
dev.restate.sdktesting.tests.BackwardCompatibilityTest$NewVersion ‑ proxyOneWayCallShouldBeDone(Client)
dev.restate.sdktesting.tests.BackwardCompatibilityTest$OldVersion ‑ createAwakeable(Client)
dev.restate.sdktesting.tests.BackwardCompatibilityTest$OldVersion ‑ startOneWayProxyCall(Client)
dev.restate.sdktesting.tests.BackwardCompatibilityTest$OldVersion ‑ startProxyCall(Client)
dev.restate.sdktesting.tests.BackwardCompatibilityTest$OldVersion ‑ startRetryableOperation(Client)
…

♻️ This comment has been updated with latest results.

[pcholakov]

Nice!

[pcholakov]

Thanks @jackkleeman, this looks great! It looks this improves on HTTP version handling too.

Sorry for the slow turnaround on this!